Many thanks for all the suggestions – much appreciated.
I had not thought about using a pallet truck and will construct my crates accordingly. The min internal dimension between a pallet truck arms is 540 mm?
I will make two crates, one for the head and another for the base, drill table, chuck key rest, etc.
One thing I will need but cannot make and don't know how to obtain; is a short length of tube to fix the head to the collar piece that bolts to the base (foot). The head and the actual base itself in one crate will be much too heavy, so I am thinking to bolt just the collar piece to the floor of the crate and fix a short bit of tube to put the head on and hold it central in the crate.
I measure the Meddings support tube to be 80 mm / 3.15" OD, and it would need to be around 400 mm long – doesn't have to be metal, just strong enough to hold the head from falling sideways.